1. Field
The present invention relates to a method of acquiring a parallel magnetic resonance image and a method thereof, and more particularly, to a method of acquiring a magnetic resonance image using a radial k-space trajectory, an apparatus thereof, and a computer readable recording medium on which a program for executing the method is recorded.
2. Related Art
Parallel magnetic resonance imaging (MRI) can acquire a magnetic resonance image more quickly than a conventional imaging method. In particular, parallel MRI acquires data using multi-channel coils.
The basic principle of parallel MRI is that a partial amount of data to the desired one is acquired simultaneously from several channels with different characteristics. As a result, an image acquiring time can be shortened. Even though insufficient amounts of data are acquired from individual channels, an image that a user wants to see can be reconstructed by appropriately combining partial amounts data from different channels.
According to conventional MRI, data are acquired from k-space and transformed using a Fourier transform technique.
The term “k-space” refers to a set of frequency component information of an MR image including magnitude information and phase information. A central region of the k-space includes contrast information of an image, and an edge portion of k-space includes information about detailed description of the image and alert information between the groups.
When conventional magnetic resonance data are acquired, the data acquisition takes place through a Cartesian trajectory. One effective parallel MRI for this Cartesian trajectory is a sensitivity encoding (SENSE) method.
Further developed parallel MRI is a method of allowing the implementation of MRI even though the data acquisition takes place through an arbitrary trajectory such as radial or spiral trajectory instead of the Cartesian trajectory.
Such developed MRI is described in an article by Pruessmann K P, Weiger M, Boernert Peter, and Boesiger Peter, entitled “Advances in Sensitivity Encoding with Arbitrary k-Space Trajectories,” Magnetic Resonance in Medicine, Vol. 46, pp. 638-651, 2001.
According to the MRI described in this article, when data are acquired in k-space not through the Cartesian trajectory but through the radial or spiral trajectory, the k-space is not often sampled equally. Thus, this described MRI undergoes a gridding operation using a Kaiser-Bessel kernel to create the Cartesian trajectory. However, the additional gridding operation may cause many errors, which may become a burden when reconstructing an image.
According to the conventional method as like the MRI described in the above article, data are inferred when the data acquisition is not undergone through the Cartesian trajectory (e.g., the gridding operation in which arbitrary data are inferred based on peripheral data). As a result, an image is not likely to be reconstructed with accuracy.